1. Field of the Invention
This invention relates to image pickup apparatus and, more particularly, to image pickup apparatus capable of selectively changing over between a field image pickup mode and a frame image pickup mode.
2. Description of the Related Art
In the image pickup apparatus capable of telephoto photography using the zoom lens or interchangeable lens, in the case when the focal length of the lens is made long, camera-shake is apt to occur. Particularly when the image pickup time is not short, this camera-shake becomes more apt to occur.
To prevent such a camera-shake, in the conventional film camera, the shutter was run at a high speed so that the exposure time was shortened, thus solving the problem.
However, in the solid state image sensor using CCD, MOS, etc. and the image pickup tube, because its sensitivity is not so high as to run the shutter at the high speed, prevention of camera-shake becomes more difficult than for the film camera.
Also, in indoor photography, etc., when photographing an object of low brightness, because of the low sensitivity, under-exposure is apt to occur.
Thus, in the case of under-exposure, there was need to compensate for the insufficiency of the exposure by changing over to flash photography, etc.
However, in the conventional image pickup apparatus, there was a problem that in the case of shooting by using light emitting means such as a flash device, in that changing over of field/frame image pickup mode in the image pickup means accompanies erring of the exposure.